{"id":1271,"date":"2020-01-03T11:08:22","date_gmt":"2020-01-03T03:08:22","guid":{"rendered":"https:\/\/wyxxt.org.cn\/?p=1271"},"modified":"2023-12-04T15:51:18","modified_gmt":"2023-12-04T07:51:18","slug":"%e8%bf%b7%e5%ae%ab%e9%97%ae%e9%a2%98%ef%bc%88%e5%b9%bf%e5%ba%a6%e4%bc%98%e5%85%88%e9%81%8d%e5%8e%86-bfs-breadth-first-search%ef%bc%89","status":"publish","type":"post","link":"https:\/\/wyxxt.org.cn\/?p=1271","title":{"rendered":"\u8ff7\u5bab\u95ee\u9898\uff08\u5e7f\u5ea6\u4f18\u5148\u904d\u5386 BFS Breadth First Search\uff09"},"content":{"rendered":"

\u8ff7\u5bab,\u53ea\u53ef\u4ee5\u4e0a\u4e0b\u5de6\u53f3\u8d70\uff0c\u8981\u6c42\u4ece\u5de6\u4e0a\u89d2\u5230\u53f3\u4e0b\u89d2\u5230\u6700\u77ed\u8def\u5f84<\/h3>\n

\n 6 6
\n 0 1 0 0 1 0
\n 0 0 0 1 0 0
\n 0 1 0 0 0 0
\n 0 1 1 0 1 0
\n 1 0 0 0 0 1
\n 1 1 0 0 0 0\n<\/p><\/blockquote>\n

\u89e3\u9898\u601d\u8def<\/h3>\n
    \n
  1. \u83b7\u53d6\u8ff7\u5bab\u56fe\uff0c\u7531\u5de6\u5230\u53f3 \u7531\u4e0a\u5230\u4e0b\u6807\u70b9(\u5982\uff1a[0,0])<\/li>\n
  2. \u4ece\u5165\u53e3\u70b9\u5f00\u59cb\u8d70\u4e00\u6b65\uff08\u4e0a\u4e0b\u5de6\u53f3\uff09\uff0c\u5217\u51fa\u6240\u6709\u53ef\u80fd\u7684\u4e0b\u4e00\u6b65 \u52a0\u5165\u961f\u5217\uff0c\u5e76\u5728\u8ff7\u5bab\u56fe\u4e0a\u6807\u8bb0<\/li>\n
  3. \u4e00\u76f4\u8d70\uff0c\u77e5\u9053\u8d70\u5230\u5f53\u524d\u70b9\u7b49\u4e8e\u7ed3\u675f\u70b9<\/li>\n<\/ol>\n

    go\u8bed\u8a00\u89e3\u6cd5<\/h3>\n
    package main\nimport (\n    \"fmt\"\n    \"os\"\n)\n\n\/\/ \u83b7\u53d6\u8ff7\u5bab\u56fe\nfunc readBfs(filename string) [][]int {\n    file, err := os.Open(filename)\n    if err != nil {\n        panic(err)\n    }\n    var row, col int\n    fmt.Fscanf(file,\"%d %d\",&row, &col) \/\/\u8bfb\u53d6\u524d\u4e24\u4e2a\u6570\u5b57\uff0c\u8d4b\u503c\u7ed9row col\n    bfs := make([][]int,row) \/\/ 6\u884c\n    for i := range bfs {\n        bfs[i] = make([]int,col) \/\/6\u5217\n        for j := range bfs[i] {\n            fmt.Fscanf(file, \"%d\", &bfs[i][j])\n        }\n    }\n    return bfs\n}\n\n\n\/\/ \u5b9a\u4e49\u70b9\u7684\u7ed3\u6784 (\u5f53\u524d\u70b9\uff0c\u4e0b\u4e00\u70b9)\ntype point struct {\n    i, j int\n}\n\n\/\/ \u5b9a\u4e49\u4e0a\u5de6\u4e0b\u53f3\u56db\u6b65\nvar dirs = [4]point {\n    {-1,0}, {0,-1},{1,0},{0,1}\n}\n\n\/\/ \u70b9\u79fb\u52a8\u5230\u4e0b\u4e00\u70b9\u5230\u4f4d\u7f6e\nfunc (p point) add(r point) point {\n    return point{p.i+r.i,p.j+r.j}\n}\n\n\/\/ \u5224\u65ad\u70b9\u662f\u5426\u5728\u8ff7\u5bab\u9014\u4e2d,\u5728\u5c31\u8fd4\u56de\u8ff7\u5bab\u56fe\u5bf9\u5e94\u5230\u70b9\u503c\uff0c\u4e0d\u518d\u8fd4\u56defalse\nfunc (p point) at(grid [][]int) {int, bool} {\n    if p.i < 0 || p.i >= len(gird) {\n        return 0,false\n    }\n    if p.j < 0 || p.j >= len(grid[p.i]) {\n        return 0,false\n    }\n    return grid[p.i][p.j],true\n}\n\n\/\/ \u8fd4\u56de\u8d70\u8fc7\u7684\u6b65\u9aa4\u56fe\nfunc walk(bfs [][]int, start, end point) [][]int {\n    steps := make([][]int, len(bfs))\n    for i := range bfs {\n        steps[i] = make([]int, len(bfs[i]))\n    }\n    queue := []point{start} \/\/\u5165\u53e3\u52a0\u5165\u961f\u5217\n\n    for len(queue) > 0 {\n        cur := queue[0]\n        queue = queue[1:]\n        if cur == end { \/\/\u8d70\u5230\u51fa\u53e3\n            break\n        }\n        for _,dir := range dirs {\n            next := cur.add(dir)\n            val, ok := next.at(bfs)\n            if !ok || val == 1 {\n                continue\n            }\n            if next == start {\n                continue\n            }\n            curStep, _ := cur.at(steps)\n            steps[next.i][next.j] = curStep + 1\n            queue = append(queue, next)\n        }\n    }\n    return steps\n}\n\n\nfunc main() {\n    bfs := readBfs(\"bfs\/bfs.ini\")\n    steps := walk(bfs, point{0,0},point{len(bfs)-1,len(bfs[0])-1})\n    for _, row := range steps {\n        fmt.Println(row)\n    }\n}\n\n\n<\/code><\/pre>\n
    \u5fc3\u5f97\uff0c\u56de\u6eaf\u6cd5\u5f3a\u4e8e\u7a77\u4e3e\u6cd5\u3002\u56de\u6eaf\u6cd5\u9700\u8981\u961f\u5217\u914d\u5408\uff0c\u7b26\u5408\u6761\u4ef6\u7684\u52a0\u5165\u961f\u5217<\/h3>\n","protected":false},"excerpt":{"rendered":"
    \u8ff7\u5bab,\u53ea\u53ef\u4ee5\u4e0a\u4e0b\u5de6\u53f3\u8d70\uff0c\u8981\u6c42\u4ece\u5de6\u4e0a\u89d2\u5230\u53f3\u4e0b\u89d2\u5230\u6700\u77ed\u8def\u5f84 6 6 0 1 0 0 1 0 0 0 0 1 0 0 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[15],"tags":[400],"class_list":["post-1271","post","type-post","status-publish","format-standard","hentry","category-15","tag-400"],"_links":{"self":[{"href":"https:\/\/wyxxt.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/1271","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wyxxt.org.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wyxxt.org.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wyxxt.org.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wyxxt.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1271"}],"version-history":[{"count":3,"href":"https:\/\/wyxxt.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/1271\/revisions"}],"predecessor-version":[{"id":1274,"href":"https:\/\/wyxxt.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/1271\/revisions\/1274"}],"wp:attachment":[{"href":"https:\/\/wyxxt.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1271"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wyxxt.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1271"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wyxxt.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1271"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}